package com.atguigu.edu.realtime.utils;

import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

/**
 * @author Felix
 * @date 2022/11/14
 * 获取线程池对象
 *      通过双重校验锁解决单例设计模式懒汉式线程安全问题
 */
public class ThreadPoolUtil {
    private static volatile ThreadPoolExecutor poolExecutor;

    private ThreadPoolUtil() {
    }

    /*
        //单例设计模式--饿汉式实现
        static {
            poolExecutor = new ThreadPoolExecutor(4,20,300, TimeUnit.SECONDS,
                new LinkedBlockingDeque<Runnable>(Integer.MAX_VALUE));
        }
        public static ThreadPoolExecutor getInstance(){
            return poolExecutor;
        }*/
    //单例设计模式--懒汉式实现
    public static ThreadPoolExecutor getInstance(){
        if(poolExecutor == null){
            synchronized(ThreadPoolUtil.class){
                if(poolExecutor == null){
                    System.out.println("~~创建线程池对象~~");
                    poolExecutor = new ThreadPoolExecutor(4,20,300, TimeUnit.SECONDS,
                        new LinkedBlockingDeque<Runnable>(Integer.MAX_VALUE));
                }
            }
        }
        return poolExecutor;
    }
}
